1. Field of the Invention
This invention is related to techniques for providing security in remote control systems; and, more particularly, to vehicle access systems featuring efficient communications and secure access code.
2. Description of the Prior Art
Remote control systems, such as those used for remote control locking and unlocking of vehicles, must meet a number of requirements in order to provide satisfactory performance. Such a system must be efficient so that it will not require frequent battery replacement. The system must also be sufficiently reliable that a user can depend on it operating within a reasonable distance from the vehicle and from all directions around the vehicle. In addition, a remote control system must have adequate security features so that it cannot be activated by an unauthorized user, whether inadvertently through stray signals from another system or deliberately by someone attempting to gain entry to the vehicle for illegal purposes.